General Questions
Why do some sharks have pointy, unserrated teeth and others broad serrated teeth?
This is a matter of form matching function. Those with more pointed teeth (i.e. sand tigers, lemon sharks, many very ancient sharks, etc.) are for stabbing/ clutching prey, namely fish, before swallowing them whole. Those that evolved more broad teeth with "tiny teeth on the teeth" (serrations) are more efficient at cutting up larger and harder prey, such as tiger sharks cutting through sea turtle shell or great whites preying on seals (fun fact great whites and others have been known to swallow large prey whole, but of course if they are say scavenging on a whale carcass, they have to slice it up).
A huge number (if not most) carcharhiniform sharks have evolved to have both types of teeth at once, typically broad serrated teeth at the top of the jaw and slender clutching teeth at the lower part of the jaw, which allows them to pursue a more wide variety of prey (& probably why they have been out-competing the more ancient lamniforms as the top shark predators for the last 10's of millions of years).
Where do I find my fossils?
Most of the quality ones come from the Peace River, if not beaches, Joshua creek, or one trip to a closed phosphate mine/ phosphate mine spoils at a museum.
Are Sharks truely "living fossils"?
As a group, sharks and rays exist among the most ancient primitive types of vertebrates (the elasmobranchs- fish with a cartilage skeleton) which have been around for at least around 400 million years. These first "sharks" resembled modern sharks in their general body plan but were still very different (especially in their jaws and teeth). All modern shark orders appeared around 100 million years ago (during the dinosaur age). Shark evolution has continued, but has gone relatively unchanged since the miocene (20-5 Million years ago). Shark evolution has slowed down because if it's not broken, why fix it??
Why were there way more sharks than anything in the miocene?
This may seem to be true when finding fossils, but you have to account for the fossil forming biases. The more something is present, is durable, and can be quickly buried the more likely it is to fossilize. Sharks constantly replace teeth (shedding tens of thousands of them in their lifetime) and they are among the most durable living materials on the planet, so they show up a lot. Other fish remains can be commonly found to reflect their abundance, but keep in mind a mere fraction less than 1% of all living materials ever fossilize (making rare finds such as a comple T. rex or giant snaggletooth shark that more special).
Why does the fossil record preserve land herbivores much more than land predators?
If you think about the plains of Africa, one of the last truly wild land regions in the world, think about the abundance of prey compared to predators. A ton more gazelle than lions right?? That's because of how trophic pyramids work, only 10% of energy is passed on from one level to the next (since eating something is very inefficient, most of the energy consumed is lost as heat, not to say bodies aren''t great for storing most of the available energy). Energy enters the system through plants, which are eaten by herbivores which are eaten by predators and maybe even another predator to that predator. Especially for warm blooded predators, constantly burning energy and the supply of prey is limited, there will not be as many as one may think.
One thing that does somewhat puzzle me is why fossil horse teeth can be so freaking common, since they lived on land and don't replace their teeth. Perhaps it is possible many were eaten by alligators, swept away by a storm, got disease struck, or just died of old age and eventually were swept into a river or creek to fossilize. Many must have existed at one time (smaller than modern horses though, we artificially bred those) as well as llamas to some degree.
What do "†" and "cf." mean?
The cross symbol denotes an extinct species or group of animals, cf. (as seen on the sand tiger page) denotes the species name may not be exactly correct/ no scientific consensus made.
Why did so many species go extinct in prehistoric time?
99.99+% of all species that have ever lived are extinct. Big species that have specialized diets (i.e. megalodons that eat whales) are more prone to extinction because they require so much food & can't adapt as quickly as small, hardy generalist animals that reproduce much faster & can adapt/evolve quicker. But in the grand scheme of things, even the largest extinctions wipe out the small adaptable things, just look at the huge Permian extinction. Huge sudden shifts in environmental factors/climate seem to be the largest killer of all. Or they evolve into something else. Or they are out-competed by other species. Present day is sad in that humans are responsible for this 5th or 6th Mass Extinction Event & only the largest extinction event of all time (Permian-Triassic) rivals it.
Extinction (in nature) is a process and over the millions of years few creatures are safe. Except horseshoe crabs lol. Those things have remained virtually unchanged for the past 300 or 400 million years, will eat anything and can handle super anoxic (oxygen poor) water. So unless we decimate them.. But definitely do not think humans are safe from extinction, regardless of politics, aliens, disease and whatnot.
What exactly is upwelling and why is it important?
Upwelling is "a physical process in oceans that involve wind-driven motion of dense, cooler and usually nutrient-rich water toward the ocean surface, replacing warmer, usually nutrient-depleted surface water" (Hines 2013). Plankton use these nutrients to thrive, which cause plankton feeders to thrive, and so on up the food chain. The nutrients stem from past ocean life that has sunk to the bottom, so upwelling basically recycles nutrients in the ocean.
How the heck are you finding many species of sharks' teeth in rivers/creeks?
I get this question far more than I ever expected, but makes sense in a way. They are fossil teeth, so they are from an ancient time, between 20-5 million years ago (regardless of many being pristine). Central & South Florida at that time was completely underwater/ marine habitat, as sea levels were at least 50 m higher from a warmer climate (less polar currents carrying water on the bottom of the ocean & less locked away at the poles; only Antarctica was starting to reform ice caps in the Miocene). I'd be surprised if Florida isn't completely or at least partially submerged in the distant future (based on past trends).
Personal Questions
Why did you make this site, are you just trying to show off?
Far from it and the process was complex (as with how I got into fossils again for good in the first place, which I'll get to sooner or later).
Basically after being laid off from my aquatic pond/wetland herbiciding job (already had plenty of FL fossils), I was kind of down & out and picked up a book on sharks from the library. This book completely revolutionized my views on sharks, as it felt like the author was right there showing me how sharks aren't just mindless killers. They have strategies, social dynamics, ways of gauging whether an unknown animal is a fellow predator or prey.. hell they don't even go in a feeding frenzy when there's a dead whale ripe for the tasting, as they take turns!! I'd always felt a special bond with Hemipristis serra since finding their large and amazing teeth, but since reading that book, it was as if the cloud of fog parted and I was starting to see them and their fellow species for how they really are. And they are truly as interesting, if not more, than any domineering apex tetrapod predator.
As for the website, it started as a kind of supplemental resource to a fictional story I wrote following the life cycle of a Hemipristis serra female. It is not too terrible, but not too great, as I was inspired by that book as well as reading an account on tiger sharks predating on dugongs and reading the book Raptor Red (a great must read for any dinosaur fan, follows the life and times of a Utahraptor and her family, with no humans in the story whatsoever, only set in the Cretaceous). Looking around at current literature, no such book existed for the Miocene seas, so I took it upon myself to write such a story. I was extremely proud of what resulted of it in August 2016 initially (still jobless at the time), but over time I started seeing factual flaws &/or "shock/entertainment value" themes, perhaps as a byproduct of seeing Jurassic Park, observing the modern seas (which aren't too rich in marine abundance compared to the Miocene) & being obsessed with Hemipristis. It is a novelty in it's own right, the only story (of noteworthy length) I know of to be only in the Miocene/no humans time traveling, but alas I am not a writer and I felt it too choresome for what it was worth to attempt and patch all of the errors (which was in danger of altering the plot/ completely changing the story, although some parts I felt really painted the scenes well). I can send you the few thousand word story upon request, but I'll likely point out what I'd like to change/ what isn't quite realistic.
Reluctantly, I began to build up this website as an alternative, but I soon realized that was a better fit for me. In order to get the "big picture" of the life & times of Hemipristis serra, there's so many natural processes to attempt to understand, understand its place in the ecosystem, why they came to be so abundant, why they went extinct, what future there is for the remaining species, and so on. Pretty soon I was having much more fun doing this than attempting to both be a masterful writer AND trying to get the facts straight.
All in all, this website is both for you, the fossil/natural history fan, to better understand the past, present, and our complex vertebrates and natural systems, as well as remind myself that it is impossible to know everything about a subject and provide facts/ figures for future reference lol. I've written so many cluttered notes on video lectures, books, documentaries, that this media form is much more consice and accessible it's almost too good to be true.
Also I could either permanently damage my skin to remind my future self how much I love fossils, or just create this masterful website, so that was a no-brainer lol.
How many fossils do you have?
Easily hundreds, mostly shark teeth that I found while digging in a Florida river or creek. I also have several fossils I bought that you cannot find in Florida, such as crocodile-like Phytosaurus teeth, Mosasaur teeth and a vertebrae (the sea monster in Jurassic world but much smaller), Orthacanthus teeth (very ancient eel like shark with bizarre double pronged teeth), and others. Non-shark vertebrate fossils that I've found myself include dugong rib fragments, alligator teeth and a vertebrae, barracuda teeth, snake & fish vertebrae, mammoth/mastodon teeth (all small &/or borken to some degree), giant armadillo scutes, turtle shell, garfish scales, mammal jaws (mostly tiny ones) and even a small broken mammal skull!
What find most took your breath away at the time of discovery?
Finding a pristine megalodon tooth is a pretty big deal, thought my chances were through the roof at my one bone valley phosphate mine trip in 2015. Found one where the tip was exposed, felt like an eternity slowly excavating the rest with a screwdriver. Some chips on it (so not perfectly pristine) but overall still a near 2" beaut.
Why are the Giant Snaggletooth sharks your favorite species?
It can change day to day, but overall these are probably at the top the most. For tooth variety, size, ferocity, abundance, their fossil teeth are amazing. But no discredit to the real sharks, they were truly formidable predators sporting such wicked teeth. The facts they preyed on dugong (also one of my favs), have a rich fossil record, and were so successful they left a modern descendant (the snaggletooth shark species in the Indo-Pacific) add to how awesome they were. I love megalodons too, but I feel they seemed almost doomed to become extinct for being so specialized on whale predation and size alone.
What do you do with your shark teeth?
I photograph (& clean if need be) all of my finds. Depending on the quality, I may take more photos and place them in a gem jar or riker mount to observe more frequently. That's pretty much it, not a huge market for selling them unfortunately (at least any I'd be willing to sell!)
Some of the lesser quality teeth (small/ broken/ not too unique) I donate to Fossil Fest (Tampa Fossil Convention) and some I make into necklaces to wear once in a blue moon (for teeth not too special, but large & complete enough to make a necklace with; with half round copper wire, pretty easy with some practice).
If there is a question not here that you wish to be answered, please contact me @ pfcp028@yahoo.com :)